Science communication has historically been inequitable, with certain voices and perspectives holding the power and dominant ways of knowing being promoted over others. Recently, there has been a push toward inclusive science communication, which values diverse perspectives and ways of knowing in collaborative conversations to solve complex socioscientific issues. However, there is a lack of both trainings in inclusive science communication for undergraduate science, technology, engineering, and mathematics (STEM) students as well as established ways to evaluate the efficacy of these trainings. To address this need, we designed a new multifactorial survey based on the Theory of Planned Behavior to assess students' attitudes/norms, self-efficacy, behavioral intents, and behaviors in inclusive science communication, which we termed the Planned Behaviors in Inclusive Science Communication (PB-ISC) Scale. We utilized expert review, exploratory factor analysis, confirmatory factor analysis, cognitive interviews, and quantitative measures to gather evidence of validity supporting the proposed use of the final 4-factor, 26-item survey. This survey can be used as a tool by science communication educators and researchers to assess students' planned behavior in inclusive science communication in response to trainings or experiences in science communication or related topics like socioscientific issues, civic engagement, and citizen science.